On Wednesday last the sloop Charming Polly, Captain Brown, and the armed brig Kitty, Captain Moore, arrived here from New York; the former, with a cargo of merchandize, sailed from thence on Tuesday the 6th instant. On Tuesday the 13th, being off Wilmington at anchor, the Rebels sent a sloop, with one piece of cannon, and three boats, one with a prow gun, full of armed men from Christiana-creek, with a view to take them;—on their appearance the brig weighed anchor, and dropped down with the tide to meet them, received the first fire from the Rebel sloop, and returned it with such ample interest, as intimidated the boats from proceeding; and the sloop, after firing four or five shot, got a boat a-head, and rowed into the creek. . . .